Water → (S)-2-Amino-4-(2-chloro-phenyl)-2-methyl-butyric acid methyl ester

HRID 1911551Notes

Reaction equation

HRID 1911551 reaction equation
[Cl:1][C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][C:3]=1[CH2:8][CH2:9][C@@:10]1([CH3:23])[C:15]([O:16][CH3:17])=N[C@H](C(C)C)C(OC)=[N:11]1.O.FC(F)(F)C(O)=[O:28].[Cl-].[NH4+]>C(#N)C>[CH3:17][O:16][C:15](=[O:28])[C@:10]([NH2:11])([CH3:23])[CH2:9][CH2:8][C:3]1[CH:4]=[CH:5][CH:6]=[CH:7][C:2]=1[Cl:1]

Participants

6

Reactant 4

HCID 962WaterHCID 6422Trifluoroacetic acidHCID 25517Ammonium ChlorideHCID 68716087(2S,5R)-2-[2-(2-Chloro-phenyl)-ethyl]-5-isopropyl-3,6-dimethoxy-2-methyl-2,5-dihydro-pyrazine

Product 1

HCID 68711125(S)-2-Amino-4-(2-chloro-phenyl)-2-methyl-butyric acid methyl ester

Reagents, catalysts & solvents 1

HCID 6342AcetonitrileSolvent

Conditions

Temperature
40 °C

Procedure

To a solution of (2S,5R)-2-[2-(2-chloro-phenyl)-ethyl]-5-isopropyl-3,6-dimethoxy-2-methyl-2,5-dihydro-pyrazine (1.22 g, 3.62 mmol) in acetonitrile (12 ml) were added water (4 ml) and trifluoroacetic acid (2 ml). The mixture was stirred overnight at 40° C. Saturated ammonium chloride solution was added and the mixture was extracted with dichloromethane three times. The combined organic layers were dried (MgSO4), filtered and evaporated. The residue was purified by column chromatography (SiO2, EtOAc/MeOH=95:5 to yield a colorless oil, (0.46 g, 52%); MS (ISP): 242.1; 244.1 ((M+H)+.).

Workup

  1. extractionthe mixture was extracted with dichloromethane three times
  2. dry with materialThe combined organic layers were dried (MgSO4)
  3. filtrationfiltered
  4. customevaporated
  5. customThe residue was purified by column chromatography (SiO2, EtOAc/MeOH=95:5
  6. customto yield a colorless oil, (0.46 g, 52%)

Sources & evidence

ORD record
ord-fab17fba59c5437e93c37c80e8472f80
Source dataset
uspto-grants-2013_12
Patent number
US08604061B2

Reaction notes

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